In recent years, Organic Light-Emitting Diode (OLED) has been widely applied in the fields of panel display and illumination. A service life of an OLED chip is prone to be adversely influenced by oxygen and water vapor. When oxygen and water vapor is infiltrated, a cathode of the OLED will be oxidated, and a demoulding and a crystallization of an organic layer may occur, and then the OLED may be aged too early or even broken. A common adverse influence includes dark spots, a pixelshrinkage and an attenuation of light intensity. According to process requirements of the OLED, packaging of the OLED enhances a mechanical strength of the OLED. In addition, the OLED may be insulated from the oxygen and water vapor. According to the industry standard, a service life of a commercial OLED product is required to be at least 10000 hours, and a storage life thereof is required to be at least 50000 hours, so it is required that a water vapor transmission rate (WVTR) is required to be smaller than 10−6 g/m2/day, and an oxygen transmission rate (OTR) is required to be smaller than 10−5 cc/bar/m2/day, and the requirement of the WVTR and OTR is more strict than that of a Liquid Crystal Display (LCD). Therefore, it has became a main objective for the development of the packaging process and devices to efficiently join the processes with respect to the cover plate and the substrate and reduce a cost of the packaging process to achieve a best mass production rate.
The OLED packaging technologies in the related art generally includes (1) UV glue edge sealing, (2) laser glass-powder packaging, and (3) thin film packaging. The first packaging method is simple, but a leakproofness thereof is poor, and a desiccant is needed, and then a service life of an OLED packaged by the first packaging method is relatively short. A cost of the third method is low, and a product packaged by this method is thin and light, and the WVTR and OTR are small, and the method is mainly appropriate for a big-size flexible substrate. However, the third method is not mature, of which a pressuretightness has not meet the requirement of the long-service-life device such as OLED television. The second method is preferred for the OLED packaging at present because of a good packaging pressuretightness, good low-temperature selectivity and a mature process of the laser-assisted glass-powder packaging process.
In the related art, the laser glass-powder packaging applies a scanning packaging method, by which an OLED substrate to be packaged is arranged on a pedestal of a laser packaging device, and scanning and heating are performed along a path of pre-sintered glass powders on the OLED substrate in sequence to complete the packaging.
However, the OLED substrate contacts the pedestal directly, and the pedestal is made of metal, such that heat transferred by the laser will be transferred to the pedestal quickly when the glass powders are scanned by the laser, and then the glass powders will be cooled quickly. When the glass powders are cooled quickly after being irradiated by the laser, the probability of occurring cracks in the glass substrate and the glass powders may be increased due to a rapid temperature change. In addition, even if the cracks are not occurred, defective products may occur due to that the durability of the glass substrate is lowered.